Photovoltaic solar concentrators typically are used to generate electrical power by concentrating sunlight onto photovoltaic devices, thereby collecting sunlight from a large area and concentrating it on a relatively small area of solar cells. Therefore, high efficiency solar cells, such as gallium arsenide-based (“GaAs”) solar cells, may be used in place of less efficient silicon solar cells, thereby producing more energy per unit area and, potentially, at a reduced cost.
Solar concentrators may be configured in various ways and typically include only refracting optics, only reflecting optics or any reasonable combination of refracting and reflecting optics. Regardless of the concentrating optics used, excess heat must be managed at the solar cell and the solar cell must be protected from the environment. Therefore, the design process generally requires a compromise between the thermal and/or protective features.
Furthermore, efficient operation of solar concentrators requires precise alignment of the optical elements with the solar cells. Indeed, a more precise alignment enables a higher degree of optical concentration, thereby reducing the aggregate solar cell cost. However, prior art solar concentrator designs typically require costly manufacturing steps to achieve precise alignment, while others sacrifice precision, and therefore efficiency, to reduce manufacturing costs.
Accordingly, there is a need for a solar concentrator that precisely aligns the primary optical elements with the solar cells in an off-axis configuration, while providing the solar cells with the requisite thermal and environmental protections.